The last of your customers have driven away, and as the sun sets, it's time to close up shop. After tending a garage sale all day, the last thing you want to do is pack everything up and deal with it ever again. Hopefully you don't have too much left -- but if you do, there are some ways to make the process easier.
First off, keep things organized! Most likely, you had at least some semblance of order during the sale itself -- clothes in one spot, books in another, toys and games in yet another. Don't disturb that order! Deal with things in categories; it will make it easier to keep track of what you're going to do with everything.
You can certainly pack things up, since you likely don't want to leave it outside all night. Large garbage bags (the black kind, preferably with the drawstring) are great for anything that isn't fragile. Clothes are easily hauled around in a garbage bag, as are toys if they don't have sharp edges.
Books and fragile things are probably better kept in boxes. You can ask your local grocery store if they would be willing to give you some of their used apple boxes or freezer-goods boxes, or check a shipping center of some sort and ask if they have leftover boxes. The integrity of the box doesn't matter much at this point, so long as you can transport your items. If worse comes to worse, reinforce the box with some packing tape.
Before you tote everything off to get rid of it, peruse it just to make sure there's nothing you could keep for the next garage sale. Collectibles will grow in value the longer you keep them, and anything rare, out-of-print, or vintage can become more in demand the older it gets. Portion off a closet corner or area of your garage to keep a box (or boxes) full of next year's items. Don't go overboard, though; you had a garage sale to get rid of things, remember!
Lots of places will take your leftover garage sale goodies, and some can give you a tax deductible donation receipt for them. Thrift stores, like Goodwill or the Salvation Army, usually have donation centers both on site and at trucks parked in department store lots. If you have a local thrift store you would rather support, call ahead to let them know what you could potentially give them. Clothing or toy drives start up around the holidays, so if you have a cause you'd like to support, you can save your stuff until then.
You've given away everything anyone wants, but you still have a large amount of stuff left, it might be time to call our friends College Hunks Hauling Junk. This is a great solution if you have larger items like furniture or bicycles; if you've only retained a few small bags, go ahead and toss them in the trash.
For a resource that will never need to be tossed out, visit GarageSaleCow.com! With one of the fastest-growing garage sale communities on the Web, GarageSaleCow.com is a great place to fulfill all of your yard sale needs.